Looked to go up, then went ahead (5)
I believe the answer is:
ogled
'looked' is the definition.
(ogling is a kind of looking)
'go up then went ahead' is the wordplay.
'up' says the letters should be written backwards (in down clue: letters go upwards).
'then' says to put letters next to each other.
'went ahead' becomes 'led' (I've seen this before).
'go' in reverse letter order is 'og'.
'og'+'led'='OGLED'
'to' acts as a link.
(Other definitions for ogled that I've seen before include "Eyed lustfully" , "Eyed lustily" , "regarded with desire" , "Looked at lecherously" , "Longingly looked at" .)